1. Statement of the Technical Field
The present invention relates to content transcoding and more particularly to content transcoding in a content distribution network.
2. Description of the Related Art
I. Content Transcoding
Multiple formats, markup languages, device capabilities and network constraints have until recently threatened to limit the promise of pervasive computing. The potential of e-business as expounded upon within the technology news media can be realized only when there is a way to bridge disparate data seamlessly, transcending multiple data protocols, devices and users. Recognizing the importance of seamless data bridging, transcoding publishers have been developed which can simplify the distribution of content across disparate elements of individual networks and global internetworks.
In that regard, transcoding publishers can enable universal access to content by dynamically adapting, reformatting and filtering content and applications for presentation and interaction within multiple disparate devices, including pervasive devices such as mobile phones, personal digital assistants (PDAs) and pagers. Specifically, transcoding publishers are server-based applications that can dynamically translate content and applications into multiple markup languages and can optimize the translated content and applications for delivery to different devices, such as mobile phones and handheld computers. In consequence, it is no longer necessary to create and maintain multiple sets of Web pages since transcoding can be performed in real time to change a master version of Web content into other required formats.
II. Content Distribution
As application providers deploy content and applications over the Internet, challenges arise in the form of processing delays and network latencies. Specifically, the placement of application content in a centralized server can compel users to traverse multiple congested networks in an attempt to effectively interact with the application. As a result, this centralized approach to deploying applications on the Internet can hinder the attainment of scalability, reliability and performance levels that are considered “mission-critical” in the deployment of a business application.
In view of these challenges, and further in view of the strategic importance of delivering requested content to end users as quickly as possible, the general problem of reducing response time has received significant attention recently. Most proposed solutions have focused upon accelerating the delivery of content through distributed caching in a content distribution network. In particular, distributed caching can be performed in one or more server devices positioned strategically about the enterprise and the Internet. These server devices can include, for instance, Web servers, caching proxy servers, surrogate servers, re-hosting servers. Accordingly, as used herein, each server device can be collectively referred to as an “edge server”. Notably, some edge servers include application off-loading technology designed to decompose monolithic applications into component parts which can be distributed to the edge of the network in a manner similar to content.
III. Transcoding Content in a Content Distribution Network
Content which has been transformed in a transcoding publisher often can be cached and re-served at the edge of the network in order to reduce the consumption of edge server resources. Yet, in many cases there may be a need to perform different content transformations for different recipients of the transformed content. In some cases, however, it can be inefficient to perform transcoding in an edge server. Likewise, it can be equally as inefficient to perform transcoding at the content source. For instance, the content source many not have an awareness of the type of end user device which will consume the content. Thus, undertaking a suitable content transformation can be difficult. By comparison, the resources of the edge server can become consumed where excessive transformations are required to accommodate the requirements of various content consumers.